SEVENTH ANNUAL YEAR BOOK— PART X. 515 



Unfortunately the percentage of nicotine varies greatly, not only in 

 different kinds of tobacco, but also in different parts of the plant, in 

 different years, and even in different parts of the same package. There 

 is more nicotine in the leaves, for instance, than in the stems. In fer- 

 mented tobacco there seems to be a certain relation between the amount 

 of nicotine and the amount of juice present, so that in general dry, thin 

 leaves do not contain so much nicotine as thick, "fat" leaves. The varia- 

 tion in percentage of nicotine in different kinds of tobacco is, according 

 to Kissling, 1893, from 4.80 to 068. From four carloads of stems, aggre- 

 gating 127,273 pounds, one American firm extracted 1,405.43 pounds of 

 nicotine, or 1.104 per cent. 



On account of the variation in the amount of nicotine in the different 

 samples of tobacco, it is practically impossible for the farmer to make up 

 an exact desired strength of tobacco dip if he prepares his own mixture 

 of leaves. He can, however, prepare a mixture which will come within 

 the limits suited to kill the scab parasites. If a solution of an exact given 

 strength is desired it will be necessary to buy prepared nicotine or pre- 

 pared tobacco dips of a guaranteed strength and reduce them to the 

 strength determined upon. 



To prepare the tobacco dip from the leaves it is best to use at least 

 21 pounds of leaves to every 100 gallons of water. Assuming that a 

 tobacco leaf is used from which the farmer might extract 2 per cent of 

 nicotine, the 100 gallons of ooze would contain slightly more than five- 

 hundredths of 1 per cent; to obtain 100 gallons of ooze of thirty-three 

 one-thousandths of 1 per cent strength, it would be necessary to use 21 

 pounds of tobacco yielding nearly 1.3 per cent nicotine. 



Directions for preparing the dip — For every 100 gallons of dip de- 

 sired take 21 pounds of good prepared tobacco leaves; soak the leaves 

 in cold or lukewarm water for twenty-four hours in a covered pot or 

 kettle; then bring the water to near the boiling point for a moment and, 

 if in the morning, allow the infusion to draw for an hour; if in the 

 evening, allow it to draw over night; the liquid is next strained (pressure 

 being used to extract as much nicotine as possible from the wet leaves) 

 and diluted to 100 gallons per 21 pounds of tobacco. This dip should be 

 used as fresh as possible, as it contains a large amount of organic ma- 

 terial which will soon decompose. 



The proportions here given — 21 pounds of prepared tobacco leaves to 

 100 gallons of water — have given very satisfactory results, especially in 

 Cape Town colony, where the reports of the scab inspectors accord this 

 home-made tobacco dip third place among the dips officially recognized. 

 In regard to one of the proprietary tobacco dips the Cape Town agri- 

 cultural department reports as follows: 



Highly spoken of by several inspectors. Very efficacious, and improves 

 the quality of the wool, making it soft and pliable. The one thing which 

 militates against its general use is its expense, hindering the poorer 

 farmers from using it. It is allowed to be one, if not the best, of the 

 patent dips in use and also the safest. 



By all means the use of a tobacco dip or of the tobacco and sulphur 

 dip, in preference to the lime and sulphur dips, is advised in case the 

 sheep to be dipped show no unmistakable signs of scab. 



